Tenley Molzahn -- one of Bachelor Jake Pavelka's frontrunners -- won sympathy on the hit ABC show by saying that her 15-month marriage ended after her ex, Ryan Natividad, cheated. But the "alleged" other woman tells the new Us Weekly (on newsstands now) that Molzahn, 25, isn't "the sweet girl everyone thinks."

"She'd only allow sex once a week...and sometimes she withheld it," says Christina Latham, who is now engaged to Natividad and denies that he ever cheated on Tenley.

Latham also tells Us Weekly that Tenley, an Oregon college admissions representative, "wouldn't let him see his family."

A Tenley pal tells Us Weekly that "She loved Ryan deeply. If there was any bad treatment, it was instigated by him."

But Latham insists, "There's no way she loved him."

For more - including embarrassing new details about Vienna's "wonky" boob job; which Bachelor finalist once dated a Backstreet Boy; how Vienna's former classmate describes her as "not the sharpest crayon in the box" and Bachelor Jake's hot high school pics -- grab the new Us Weekly today!